The AM Forum

Larry - WA1LGQ and I were chatting locally on 28.991 MHz this morning as he was giving his little Heathkit 10 Meter Lunchbox a workout. It was our lucky day as Gary - G0FWX happened to see our signals on his panadapter and he broke in to say hello. The recording documents the exchange between Larry as he is running 1/2 watt and Gary who is located near Cambridge in England. It was an unexpected bit of excitement on an otherwise quiet band!

Rob W1AEX

Very cool at 1/2 watt.  

Brilliant! -  as the Brits say.

The classic saying applies here:  "You can work the whirl on a wet noodle when 10M is open."

Amazing difference between 1/2 to 15 watts.  About 14 dB technically.

T

Great fun : )

I would like to know more about his set up. Lunch box? I know what that is but antenna, its  height  etc. That interests me. I am working on a 10M transceiver project right now. is therea web site or something?
Don VE3LYX

Hi Don, the "lunchbox" is a Heathkit HW-19 simple transceiver.http://www.heathkit-museum.com/ham/hvmhw-19-29-30.shtml (http://www.heathkit-museum.com/ham/hvmhw-19-29-30.shtml)

I don't know why the output is only about .6 watts. Maybe the rig needs service. I have not done anything to it except clean the tube sockets and tweak the adjustments. The antenna used was a simple homemade vertical "J-pole" made from wire and a piece of ladder line modeled after this design: http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=19622 (http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=19622)

The antenna is simply pulled up into a tree, and the bottom of the antenna is at about 35ft height. The mic I used on the rig is a D-104 with the original preamp gutted and replaced with a single FET preamp. It drives the modulator pretty heavily. Actually this was the first QSO that I made with the thing! The transmitter needs a vfo of some kind or a handful of xtals.

What kind of setup are you thinking about setting up?

..........Larry

Yes I am familiar with the "lunch box" sets. Neat radios. Thanks for the antenna info. That interests me greatly.
What rig for me? I have been working on this rig here, a two tube transceiver. I have it running right now on 29000 and it has a stable VFO. I have it modulating but it could use a bit stronger kick.  It has a  regen for a recvr Both tx VFO and regen are hartley circiuts. It is capable as a stand alone of probaby 3.5 watts put if everthing is perfect but I have no problem with the idea of building a small linear for it when it is parked in the shack, It is portable though and built in a small file box. I also have a 6sa7 mixer tube rig i built. It, like yours, has more then enuf modulation available and puts out about 7 watts RF. It is really hard on the mixer tubes though. I just need to push them too hard once and they are done. I need to cut back on the Plate B plus and I am using them above their proper values. The other tubes in the rig can stand almost double. I built it on 40m but that is pointless to the point of being stupid. I can move it to ten easy enuf and will. During my probationary phone days with my first license before I got my advanced I was limited to 10M phone or Cw anywhere so I got to enjoy it and knew how to work the band. Now 30 years later I have a renewed interest in 10M because of this AM thing. I know when ten is open power is almost irrelevant. Seems like a good place to be with this stuff. I was very interested in your success. Thanks for taking the time to post.
Good DXing
Don